建立一个视图salary，该视图包括了系号和(该系的)平均工资两个字段，正确的SQL语句是( )。

A．CREATE VIEW salary AS系号,AVG(工资)AS 平均工资 FROM 教师;GROUPBY 系号
B．CREATE VIEW salary AS SELECT 系号,AVG(工资)AS 平均工资 FROM 教师;GROUP BY 系名
C．CREATE VIEW Salary SELECT 系号,AVG(工资)AS 平均工资 FROM 老师;GROUP BY 系号

D．CREATE VIEW salary AS SELECT 系号,AVG(工资) AS 平均工资 FROM 老师;GROUP BY 系号